DIY

abbreviation earlier than 1955

DIY is of course an abbreviation of do it yourself, and both terms refer to the carrying out of a task by oneself, especially around the home. The entries for these terms are currently being revised by OED editors. The earliest use of do it yourself as a phrase found so far dates from the nineteenth century (without the later associations with home improvement):

1845 Richard H. Barham Ingoldsby Legends (1905) 288 If it’s business of consequence, Do it yourself!

By 1910, the phrase being used as an adjective:

1910 Popular Science Monthly May 493 At the Boston Tech a method has been in vogue for long that is there deemed highly satisfactory—it is known as the ‘do-it-yourself method’.

But our evidence for the initialism DIY currently goes back only as far as 1955: